This invention concerns, in general, the field of light firearms, both long and short barrelled such as parallel barrel or over-and-under shotguns, rifles, handguns etc., and in particular refers to a safety device for these arms, namely a mechanical supplementary safety device in the form of a false cartridge.
On the one hand the use of so-called false cartridges is already established: devices inserted into the chamber of the barrel(s) of a light firearm when it is not in use, in place of a real cartridge, with view to at least preventing the gun going off accidentally and indicating that it cannot be arbitrarily used. These means however have no real safety device function in the sense that they cannot effectively block abusive use of the firearm since the false cartridge may easily be removed without specific tools even by a child or by unauthorised and incompetent persons.
On the other hand, though the firearms mentioned above are usually equipped with safety catches with the function of preventing them going off accidentally, for example by blocking the trigger mechanism and/or the hammer action, today there is a pressing demand and consequent need to equip these arms with an additional safety device that can be activated and deactivated by a personalised means available only to the owner of the firearm or someone delegated thereby, thus avoiding effective use of the firearm by unauthorised persons.
One purpose of this invention is to offer a supplementary safety device created in the form of a false cartridge which can be inserted and stably locked in the chamber of light firearms without the possibility of removal other than voluntary and only by using a specific means correlated to the device itself.
Another purpose of the invention is to supply a mechanical safety device that fully corresponds to the current, sought-after requirement of increased safety in the use of light firearms such as to permit their use only and exclusively to those who have a personalised method, such as a key, that can control and remove the device once the latter has been activated.
A further purpose of the invention is to create and supply a safety device for light firearms, shotguns, rifles, handguns and similar that is supplementary to the safety catches with which these firearms are already equipped.
Yet another purpose of the invention is to supply a safety device for the above mentioned firearms that has two distinct locking sections for maximum efficiency: the first section can be voluntarily activated and deactivated by a specific and personalised method, while the second section, normally inactive, is activated following surreptitious attempted breakage and removal of the device when it is locked in the barrel of a firearm.
The invention achieves these purposes with a mechanical safety device for light firearms, with a first body including a lock with a rotating part controlled by a specific key. A second body is linked to the first body and is axially movable with respect to the second body without rotating with respect to the second body. The second body is axially movable between a position of unlocking when distant from, and locking when close to, the first body. A screw pin is drivable in rotation in the first body without moving axially in the first body. The screw pin is connected to, and controlled by, the lock for its rotation, and is linked directly or indirectly with the second body for the movement thereof between the positions of unlocking and locking following the turning of the screw pin. A flexible element deformable by compression, is located between the first and second bodies in order to expand radially and project peripherally from the bodies when the second body is in the locking position, thus creating the locking of the device in the chamber of the barrel in which it is housed.
Correspondingly, the safety device proposed herewith, substantially in the form of a false cartridge or of a form suitable for insertion into the chamber of a firearm, possesses first of all a radially expandable portion controlled by a lock and specific key for locking/unlocking it in the barrel in which it is lodged, thus making it removable only voluntarily.
However, depending on the state and/or the lubrication of the barrel cartridge chamber internal surface, this controlled expansion lock might not prevent the sliding and forced ejection of the device if axial thrust were to be applied by means of a tool such as a rod, inserted into the muzzle of the barrel.
So the second locking portion of the device is aimed at preventing all unauthorised forced removal, thanks to an accentuation of the locking action. In fact any axial thrust applied to the device with the intention of ejecting it from the part of its introduction into the barrel results in activation of this second portion which, expanding, tightens against the interior of the barrel; and the greater the thrust the greater the tightening. The advantages of the new supplementary safety device invention may therefore be summarised as follows:
great ease, convenience and immediacy of use;
maximum efficiency and reliability in preventing unauthorised use of the firearm;
possibility of breakage minimised, and even more so if the command lock is
made in drill-resistant material.
Moreover, its configuration and absence of appendices mean that when the device is set in place in the chamber it offers no part that might be gripped by an extracting tool. Lastly, a safety device of this type may be easily manufactured and adapted with the same efficacy and safety to firearms of all calibres, without any modification of the firearm whatsoever.